Novel Phase-Sensitive Full-Waveform Tomography for Seismic Imaging

Abstract

Full-waveform tomography (FWT) is increasingly recognized as a pivotal technique for delineating high-resolution subsurface properties. Despite its significant potential, practical applications of FWT encounter persistent challenges, particularly in dealing with local minima and cycle-skipping problems. These difficulties often arise and are intensified by the least-squares (L2) norm’s intrinsic insensitivity to phase mismatches. To address these challenges, we have redefined the traditional L2 norm misfit function by incorporating a time shift within the synthetic waveform. This shift is determined by the temporal discrepancies between the observed and synthetic waveforms, identified through a cross-correlation technique. This approach, termed phase-sensitive FWT, integrates phase differences into the new misfit function, thus significantly mitigating the cycle-skipping problem. Numerical experiments demonstrate that PSFWT reduces dependence on the initial model and achieves more accurate inversion results compared with the traditional L2 norm method, highlighting its potential for enhancing the precision and reliability of seismic imaging.